• Proceedings of the Korean Institute of Interior Design Conference
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• 2006.05a
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• pp.97-98
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• 2006

This study proposes a method of generating steel house shop drawing in an automated design method, reducing construction manpower and period. With one hour fire-resistant approval code, reflecting work ability and efficiency, steel-framed house market is expected to extend from one or two story house to multi-purpose facilities up to four story height. More models have been constructed in this system than the first appearance of fire-resistant approval in Korea in 1997 Also, cost estimation of components such as frame walls, roof trusses and floors is obtained with shop drawings. Also, the lack of suppliers of steel framed house shop drawing and unstandardized drawing method get constructors have difficulty in understanding its design. In steel framed house industry, shop drawings are essential part in building and constructing framework and they have major effects on construction deadlines and expenses. By exploring method of shop drawing automation, this study aims to optimize work flow with a standardized drawing method. The proposed system can be applied to manufacturing automation in domestic industry of factory-built panelizing method in the near future.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.1450-1455
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• 2005

This paper describes a DR construction for land navigation and the sigma point based receding horizon Kalman FIR (SPRHKF) filter for DR/GPS hybrid navigation system. A simple DR construction is adopted to improve the performance both of the pure land DR navigation and the DR/GSP hybrid navigation system. In order to overcome the flaws of the EKF, the SPKF is merged with the receding horizon strategy. This filter has several advantages over the EKF, the SPKF, and the RHKF filter. The advantages include the robustness to the system model uncertainty, the initial estimation error, temporary unknown bias, and etc. The computational burden is reduced. Especially, the proposed filter works well even in the case of exiting the unmodeled random walk of the inertial sensors, which can be occurred in the MEMS inertial sensors by temperature variation. Therefore, the SPRHKF filter can provide the navigation information with good quality in the DR/GPS hybrid navigation system for land navigation seamlessly.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2014.05a
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• pp.42-43
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• 2014

Few studies on crew productivity has been conducted, although the data is significant for time and cost estimation. Crew productivity data was collected for over 9 months from a nuclear power plant and analysed in order to identify factors driving the productivity. It was revealed that the crew productivity of form work, rebar work and concrete pouring work was 45.64(㎡/crew·day), 2.93(t/crew·day), 110.25(㎡/crew·day) on average respectively. Moreover, 'nightwork', 'No. of workers per crew' and 'total work amount' were identified as drivers.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2016.05a
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• pp.162-163
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• 2016

This paper presents a mathematical model for optimizing earthwork allocation plan that minimizes earthwork cost. The model takes into account operational constraints in the real-world earthwork such as material-type (i.e., quality level of material) and quantities excavated from cut-sections, required quality of material and quantities for each embankment layer, top-down cutting and bottom-up filling constraints, and allocation orders. These constraints are successfully handled by assuming the rock-earth material as the three dimensional (3D) blocks. The study is of value to project scheduler because the model identifies the optimal earth allocation plan (i.e., haul direction (cut and fill pairs), quantities of soil, type of material, and order of allocations) expeditiously and is developed as an automated system for usability. It is also relevant to estimator in that it computes more realistic earthworks costs estimation. The economic impact and validity of the mathematical model was confirmed by performing test cases.

• Journal of the Korea Society for Simulation
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• v.13 no.2
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• pp.35-43
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• 2004

The purpose of this study is an economic analysis of power plant utilities by comparing electricity generating cost including environmental costs. Considering the enormous role of electricity in the national economy, it is very important to study the effect of environmental regulation on the electricity sector. Because power utilities need for large investment during construction, operation and maintenance, and also require much construction lead time. Economic analysis is the important process in the electric system expansion planning. This paper compares the costs of electricity generation including environmental costs between a coal-fired power plant and an LNG combined cycle power plants. With the simulation, this study surveys the sensitivity of fuel prices, interest rate and carbon tax. In each case, this sensitivity can help to decide which utility is economically better in environmental regulation circumstance.

• Journal of the Korea Institute of Building Construction
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• v.6 no.2 s.20
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• pp.65-72
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• 2006

The amount of water demand at large buildings is increasing with the concentration of population to city and a rise in the standard of living in the city area. In this reason the Water Shortage is expected and a problem of water pollution by the city sewerage is increasing. One of method of saving city water demand and city sewer is applying recycling water system witch make used water reuse by purification of water. The application of recycling water system witch make used performed since the application of Lotte World Complex. But the popularization of this system is not activated because of cost problem and feeling of people to the water recycled. So in this study, provide application method for recycling water system by propose the estimation method of optimal sizing of recycling water system.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2018.11a
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• pp.85-86
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• 2018

In this study, we previously conducted a quick evaluation of cement powder map using mesiline and hydrometer. The experiment also confirmed the possibility of rapid quality evaluation of cement powder. In this study, further studies have been conducted to apply speed and cost more economical than conventional methods, and the possibility of applying this research is to be analyzed. The result of the experiment was 500 mL of a bottled water bottle with a solid edge for measurement convenience, and the hydrometer was determined to be B type. In addition, density values of each other by powder during the same time period are considered to be measurable, indicating large differences.

• Korean Journal of Construction Engineering and Management
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• v.21 no.1
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• pp.50-60
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• 2020

Estimates of project costs in the early stages of a construction project have a significant impact on the operator's decision-making in important matters, such as the site's decision or the construction period. However, it is difficult to carry out the initial stage with confidence because information such as design books and specifications is not available. In previous studies, case-based reasoning was used to predict initial construction costs, and genetic algorithms were used to calculate the weight of the inquiry phase among them. However, some say that it is difficult to perform better than the current year because existing genetic algorithms are calculated in random numbers. To overcome these limitations, correlation numbers using correlation analysis rather than random numbers are reflected in the genetic algorithm by method of local search, and weights are calculated using a hybrid genetic algorithm that combines local search and genetic algorithms. A case-based reasoning model was developed using the weights calculated and validated with the data. As a result, it was found that the hybrid GA-CBR applied with local search performed better than the existing GA-CBR.

• Korean Journal of Construction Engineering and Management
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• v.5 no.6 s.22
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• pp.138-145
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• 2004

The construction duration for any building or facilities such as high school building influence the quality of the building as well as the total cost for them. Since there are no guidelines to estimate construction duration correctly, an employer(or owner) estimate it by their own experience or intuition. Therefore some conflicts related to construction duration happen between contract parties during construction. The purpose of this study is to suggest a predictive model which helps decision makers calculate exact net working days for high school building construction at the early stage of the construction project. To measure net working days for high school construction, 15 data were collected from actual spot in Incheon region. Multiple linear regression analysis was conducted to obtain the model which calculate construction duration for the substructure, the superstructure and the finishing works. total construction duration could be obtained by adding net working days to non working days which would be based on the meteorological statistics for Incheon region since 1974 to 2003.

• Plant Journal
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• v.7 no.2
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• pp.39-43
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• 2011

Due to the recent uncertainty of market situations such as the escalation of petroleum prices, increased production capacities of plants, limitations of the available EPC (Engineering, Procurement, Construction) contractors, and the increase of raw material prices, EPC contractors have had a tendency to include a higher reserve contingency in the lump-sum turnkey contract price. In order to overcome the changes in the market, the plant project construction industry has started to apply the converted lump-sum turnkey contract in plant construction market. This study was focused to find the associated risks and to analyse the identified risks on recent trend of application of the new contract type, which is the converted lump-sum turnkey contract. It was recognized from the analysis that quality and cost have more high priority risks than other project objectives. This paper also suggests the mitigation plan for identified risks to achieve project objectives appropriate to the converted lump-sum turnkey project from the viewpoint of an EPC contractor keeping transparency with owner.